Song Dynasty
Revival of Ch'an Buddhism

The "Golden Age of Zen" refers to Ch'an in the Tang Dynasty, from Hui-neng through the "five houses" of his successors. The Tang Dynasty lasted from 618 to 906-907 AD, and Buddhism became the dominant ideology, being adopted by the imperial family. But in 845 Emperor Wuzong "shut down 4,600 Buddhist monasteries along with 40,000 temples and shrines, forcing 260,000 Buddhist monks and nuns to return to secular life" according to a Wikipedia article. Apparently the ban was lifted a few years afterward, but Buddhism didn't regain its dominance.

The Tang Dynasty was succeeded by half a century known as the Five Dynasties and Ten Kingdoms era, which in turn was followed by the Song Dynasty from 960 to 1279 AD. During the Song rule, Ch'an Buddhism once again flourished, guided by notable Ch'an masters such as Dahui, Foyan and Mi-an.

Dahui was the 12th generation of Zen masters in the Lin-chi (Japanese: Rinzai) tradition. Lin-chi, whose teacher was Huang-po, died in 867 AD. Dahui advocated koan, or kung-an, practice as the fastest way to enlightenment, but he suppressed his own teacher's collection of such teaching stories and conundrums (Blue Cliff Record) because it had become superficially used as intellectual study material. He was a vigorous critic of the Caodong (Ts'ao-tung; Japanese: Sōtō) tradition, which he termed "the heretical Ch'an of silent illumination."

Dahui had become a monk at age 17, practiced Caodong meditation for two years, then studied all the records of the "five houses" of Ch'an, becoming proficient in an intellectual understanding of them. At age 21 he went to study under Zhan Tangzhun (Chan-t'ang Wen-chun), a master of the Huang-lung branch of the Linji school. More than five years later, when Tangzhun was ill, he sent him to study under Yuan-wu Keqin. In 1125, when he would have been 35 or 36, Dahui had his first breakthrough. He later recalled:

Master Yuan-wu ascended the high seat in the lecture hall at the request of Madame Chang K'ang-kuo. He said, "Once a monk asked Yun-men this question: 'Where do all the Buddhas come from?' Yun-men answered: 'The East Mountain walks over the water' (Tung-shan shuei sheng hsing). But if I were he, I would have given a different answer: 'Where do all the Buddhas come from? As the fragrant breeze comes from the south, a slight coolness naturally stirs in the palace pavilion.' When I heard this, all of a sudden there was no more before and after. Time stopped. I ceased to feel any disturbance in my mind, and remained in a state of utter calmness.

But Yuan-wu apparently sensed that Dahui hadn't yet made the complete trip and told him:

It is indeed not easy to arrive at your present state of mind. But unfortunately, you have only died but are not yet reborn. Your greatest problem is that you do not doubt words enough. Don't you remember this saying? "When you let go your hold on the precipice, you become the master of your own fate; to die and afterward come to life again, no one can then deceive you."

Yuanwu then gave Dahui the koan, "To be and not to be  it is like a wisteria leaning on a tree" to work on, and after six months Dahui achieved the final breakthrough.

The following year, 1126, the Manchus captured the Song capital along with the emperor. The capital was moved south to Hangzhou under a self-appointed new emperor, and the Southern Song dynasty began. Dahui also moved south, and in 1137 the prime minister, who was a student of Dahui, appointed him as abbot of the Ching-shan monastery in the capital. Within a few years his sangha grew to two thousand monks and laymen, including many high-ranking officials, and Dahui became the leader of Buddhism in the Song dynasty.

He fell out of favor with the prime minister, was exiled to Hunan in 1141 and later to plague-infested Guangdong. He was pardoned in 1155 and allowed to return to the Ching-shan monastery. He wrote a great final verse for his disciples shortly before his death, quipping: "Without a verse, I couldn't die." (There was a tradition among the Zen masters of writing final verses before they died.)

Birth is thus
Death is thus
Verse or no verse
What's the fuss?

A Zen master without a sense of humor would be for the

The Buddhas of past, present, and future,
and all of their scriptural discourses,
are all in your original nature, inherently
complete. You do not need to seek, but you
must save yourself. No one can do it for you.
~ Hsueh-feng (822-908)

Foyan was an active volcano producing paradox and consternation for his listeners. The following excerpts are from Thomas Cleary's translation of Instant Zen.

If you don't ask, you won't get it; but if you ask, in effect, you've slighted yourself. If you don't ask, how can you know? But you still have to know how to ask before you can succeed.... Remember the story of the ancient worthy who was asked, "What was the intention of the Zen Founder in coming from India?" Amazed, the ancient said, "You ask about the intention of another in coming from India. Why not ask about your own intention?"

I see that symptom frequently, and people fall back into it sleepily even after it's pointed out.

When my teacher [Wuzu Fayan] was with his teacher, his teacher used to say, "This path is a natural subtlety attained by oneself," generally focusing on the existence of innate knowledge.

I always tell you that what is inherent in you is presently active and presently functioning, and need not be sought after, need not be put in order, need not be practiced or proven. All that is required is to trust it once and for all.

See "The Mind of Absolute Trust" by Seng-Ts'an, the 3rd Patriarch of Ch'an, for a classic and beautiful exposition of trust in what's within.

... Just because I wondered deeply, I later attained penetrating understanding.... If you do not reflect and examine, your whole life will be buried away.

Whatever you are doing ... there is something that transcends the Buddhas and Zen Masters; but as soon as you want to understand it, it's not there. It's not really there; as soon as you try to gather your attention on it, you have already turned away from it.... Does this mean that you will realize it if you do not aim the mind and do not develop intellectual understanding? Far from it  you will fail even more seriously to realize it. Even understanding does not get it, much less not understanding!

The universal Way has no form, Truth has no opposite; so they are not in the realm of perception or cognition. There are neither coarse no fine conceptions in it.
~ Nanquan (747-834)

The ancients had a lot of complications to help you, such as Xue-feng's saying, "The whole earth is you," Jiashan's saying, "Pick out the teacher in the hundred grasses; recognize the emperor in a bustling market place," and Luopu's saying, "As soon as a particle of dust arises, the entire earth is contained therein; the whole body of a lion is on the tip of a single hair." Take these up and think about them over and over again; eventually, over time, you will naturally find a way to penetrate. No one can substitute for you in this task; it rests with each individual, without exception.
~ Yunmen (d. 949)

I haven't found any biographical information on Mi-an, but here are a few short excerpts of his thinking:

Those who have not learned are in confusion; not relying on the source, they abandon their families, quit their jobs, and wander around in misery, running north and south looking for "Zen" and "Tao" and seeking "Buddha" and "Dharma" on the tongues of old monks all over the land, intentionally waiting for their "transmission," unaware they have missed the point long ago.
From Instant Zen: Waking Up in the Present, Thomas Cleary (trans.)

When you are totally alive
and cannot be trapped or caged,
only then do you have some independence.
Then you can be in the ordinary world
all day long without it affecting you.
From Zen Essence: The Science of Freedom, Thomas Cleary (trans.)

The reason this path has not been flourishing in recent years is nothing else but the fact that those who are acting as teachers of others do not have their eyes and brains straight and true.

They have no perception of their own, but just keep fame and fortune and gain and loss in their hearts. Deeply afraid that others will say they have no stories, they mistakenly memorize stories from old books, letting them ferment in the back of their minds so they won't lack for something to say if seekers ask them questions.

They are like goats crapping: the minute their tails go up, innumerable dung balls plop to the ground! Since students do not have clear perception, how are they supposed to distinguish clearly? Students believe deeply, with all their hearts; so unseeing individuals lead unseeing crowds into a pit of fire.
From Instant Zen